According to an annual report published on Wednesday by China's State Oceanic Administration, average coastal sea levels in 2016 were up 38 millimeters compared to the previous year, and saw record-breaking highs in the months of April, September, November and December.

"Against the background of global climate change, China's coastal air and sea temperatures have soared, coastal air pressure has fallen and sea levels have also soared," it said.

It warned that high sea levels would lead to problems like coastal erosion as well as more frequent and severe typhoons.

It added that vulnerable coastal regions needed to step up their flood prevention efforts by improving drainage systems and building dykes and dams. Underground water extraction also needed to be cut in order to ease the risk of subsidence.

China's coastal waters have risen 3.2 millimeters per year since 1980, higher than the global average increase over the period. Sea temperatures over the 1980-2016 period have been rising by an average of 0.21 degrees Celsius per decade.

The administration said at a press briefing on Wednesday that marine disasters caused 60 deaths and direct economic losses of 5 billion yuan ($725.95 million) in 2016. It also warned that marine pollution remained severe.